ACHATINELLA MUSTELINA. 347 



about half a dozen as light as the banded form from the west- 

 ern ridge. Fig. 10 is a very unusual color-pattern in this 

 colony, and figs. 106, c show extremes of shape but normal 

 coloring. 



In a small area of probably two or three square rods we 

 found snow-white shells with the columella dull lavender or 

 white, summit white. This is evidently a recent albino muta- 

 tion which has not had time to spread far. They occur with 

 the ordinary pattern of the surrounding colony. The speci- 

 mens I found were all dextral. 



Further up the same ridge the shells are intermediate in 

 pattern between the preceding colony and that of the western 

 ridge of Popouwela. 



A colony in coll. Spalding from the "southern ridges of 

 Popouwela' varies from the patterns of pi. 63, figs. 12, 12a 

 to black with white bands or white flecks, resembling the 

 lymaniana pattern. One is figured, pi. 63, fig. 11. 



On the Popouwela-Lihue division ridge Mr. Spalding found 

 a dextral and sinistral form like that shown in pi. 63, fig. lOc, 

 except that the white sutural band is a trifle wider. With 

 them, without intergrading specimens, there is a smaller form 

 closely resembling turbiniformis, but with less concave spire, 

 pi. 62, fig. 21. This may be regarded as the western limit of 

 the turbiniformis stock. The shells are dextral, and from 

 their smaller size, different coil and markings, probably do 

 not hybridize with their larger dark companions. 



Further up the same ridge, Mr. Spalding took lighter bi- 

 colored shells with others of multilineata pattern (pi. 63, figs. 

 12, 12a). 



It appears that between the main northeastern ridge from 

 Kaala and the Popouwela-Lihue ridge, the prevalent form is 

 a shell with the white sutural band wider than Mokuleia mus- 

 telina on the west, and narrower than Lihue "bicolor," east- 

 ward. The darkest forms are near the lower limit of shell 

 country, while on the higher ridges the lighter, multilineata 

 patterns prevail ; but there are exceptions. It will be noted 

 that in the Main Range banded forms are also chiefly devel- 

 oped on the ridges. 



